Analyzes data and prepares original maps, charts, and drawings from aerial photographs, and standard mathematical formulas and photogrammetric techniques to identify, scale, and orient geodetic points, elevations, and other planimetric or topographic features and cartographic detail.

Appropriate tables and graphs are used to calculate "unit" friction losses; for this purpose, precise altimetric and planimetric plans containing pipeline layouts provide the best and most complete information (Fig 35).

The final drawings, showing all technical details of the system, are then finished and will accompany the topographical profile (showing also the pipeline's hydraulic gradients) and the planimetric map showing the exact location of all system components.

The main characteristics of the LANDSAT data are their worldwide and repetitive coverage; synoptic view; uniformity over time and over large areas; multispectoral nature; availability in digital form for computer analysis; planimetric (near orthographic) images; the ready availability, ease of use and inexpensiveness of data (as of October 1982, a 18.5 cm × 18.5 cm colour print covering 34,000 square kilometres cost US$45).